Hatton: Mexican petunia a continuously blooming plant

Friday

Feb 28, 2014 at 5:59 PM

I have mentioned Mexican petunia for various reasons a number of times throughout the years. Not a petunia or even in the same family as petunias, Ruellia is a native of Mexico. It is a genus of about 150 species of perennials, soft-stemmed or woody shrubs and subshrubs.

Ruellia simplex, aka Ruellia brittoniana and others, is a heat-loving, heavily blooming perennial. Varying in height from about 6 inches to 4 feet or more, its flowers come in shades of purple to pink and scarlet as well as white. Flowers only last one day, but once in bloom, the plant provides a continuously blooming show. It blooms in my gardens from about June to late September.

Once established, it is drought tolerant. Interestingly, it also grows equally well in very wet soil and high humidity areas. These plants are invasive in some parts of the country, but in our area, they can be aggressive, but are easily controlled. They spread by seeding and rhizomes and also can be easily propagated by stem cuttings.

The genus Ruellia honors Jean de la Ruelle (1474-1537), a French herbalist and physician to the king of France. A favorite variety, Ruellia simplex "Katie," is a dwarf that is generally less than a foot tall.

Katie was named after Katherine "Katie" Ferguson who grew up in Odessa, went to prep school in San Antonio and graduated with an art degree from Mount Holyoke College in Massachusetts. Upon graduation, she spent a year in Italy learning the culture, language and its art. She then embarked on a career in women's clothing as a buyer and designer.

After marriage and the birth of a daughter, she began landscaping her home in Houston and discovered a passion for plants and gardening. Changing careers, she began working in the nursery industry and ultimately, in 1982, purchased the nursery where she worked much of the time. Shortly after the purchase, employees discovered the dwarf ruellia and told the previous owner about it. After he had ascertained that it was a plant worthy of reproducing and selling, he named it after Katie.

Unless in a microclimate, Katie will not overwinter in our area and must be grown as an annual. Some ruellias are reliably perennial here, while others are not. Further, some will perform for years in the proper microclimate although they are supposedly not hardy to our zone 7.

Since they are so easy to propagate, why not try a few in different areas? Mine do the best against the south side of the house, getting some protection from the cold. In less protected areas, I have found them to die out slowly over a few years. Being heat lovers, they come up late in the spring, so be patient.

Although I have never done it, they can be grown in containers, and I have seen them growing as standards, which are both unusual and interesting. I have never experienced any problems with these plants. They seem to be disease and pest free.

Bob Hatton is a community volunteer. He can be reached at gardenguy1@suddenlink.net.

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